Late on November 14, 2017, a slow-moving weather system in the Mediterranean brought torrential rain and flash floods to Greece. Among the hardest hit places was Mandra, a town west of Athens. Floods there left hundreds of people homeless and claimed several lives.

The GPM satellite is the core of a rainfall observatory that includes measurements from NASA, the Japan Aerospace Exploration Agency, and five other national and international partners. These rainfall totals are regional, remotely-sensed estimates, and local amounts can be significantly higher when measured from the ground.

NASA Earth Observatory image by Joshua Stevens, using IMERG data from the Global Precipitation Mission (GPM) at NASA/GSFC, Landsat data from the U.S. Geological Survey, and ASTER GDEM data from NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. Story by Adam Voiland.